The genetic diversity and applicability assessment of autosomal STRs among Chinese populations by a novel Fixation Index and Nei’s index

2018 ◽  
Vol 31 ◽  
pp. 49-58 ◽  
Author(s):  
Caiyong Yin ◽  
Chuwei Deng ◽  
Xiaoqin Qian ◽  
Huijie Huang ◽  
Yanfang Yu ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Grimar Abdiel Perez ◽  
Pumipat Tongyoo ◽  
Julapark Chunwongse ◽  
Hans de Jong ◽  
Anucha Wongpraneekul ◽  
...  

AbstractThis study explored a germplasm collection consisting of 112 Luffa acutangula (ridge gourd) accessions, mainly from Thailand. A total of 2834 SNPs were used to establish population structure and underlying genetic diversity while exploring the fruit characteristics together with genetic information which would help in the selection of parental lines for a breeding program. The study found that the average polymorphism information content value of 0.288 which indicates a moderate genetic diversity for this L. acutangula germplasm. STRUCTURE analysis (ΔK at K = 6) allowed us to group the accessions into six subpopulations that corresponded well with the unrooted phylogenetic tree and principal coordinate analyses. When plotted, the STRUCTURE bars to the area of collection, we observed an admixed genotype from surrounding accessions and a geneflow confirmed by the value of FST = 0.137. AMOVA based on STRUCTURE clustering showed a low 12.83% variation between subpopulations that correspond well with the negative inbreeding coefficient value (FIS =  − 0.092) and low total fixation index (FIT = 0.057). There were distinguishing fruit shapes and length characteristics in specific accessions for each subpopulation. The genetic diversity and different fruit shapes in the L. acutangula germplasm could benefit the ridge gourd breeding programs to meet the demands and needs of consumers, farmers, and vegetable exporters such as increasing the yield of fruit by the fruit width but not by the fruit length to solve the problem of fruit breakage during exportation.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Li-Yun Lin ◽  
Hui-Ying Huang ◽  
Xue-Yan Liang ◽  
Dong-De Xie ◽  
Jiang-Tao Chen ◽  
...  

Abstract Background Thrombospondin-related adhesive protein (TRAP) is a transmembrane protein that plays a crucial role during the invasion of Plasmodium falciparum into liver cells. As a potential malaria vaccine candidate, the genetic diversity and natural selection of PfTRAP was assessed and the global PfTRAP polymorphism pattern was described. Methods 153 blood spot samples from Bioko malaria patients were collected during 2016–2018 and the target TRAP gene was amplified. Together with the sequences from database, nucleotide diversity and natural selection analysis, and the structural prediction were preformed using bioinformatical tools. Results A total of 119 Bioko PfTRAP sequences were amplified successfully. On Bioko Island, PfTRAP shows its high degree of genetic diversity and heterogeneity, with π value for 0.01046 and Hd for 0.99. The value of dN–dS (6.2231, p < 0.05) hinted at natural selection of PfTRAP on Bioko Island. Globally, the African PfTRAPs showed more diverse than the Asian ones, and significant genetic differentiation was discovered by the fixation index between African and Asian countries (Fst > 0.15, p < 0.05). 667 Asian isolates clustered in 136 haplotypes and 739 African isolates clustered in 528 haplotypes by network analysis. The mutations I116T, L221I, Y128F, G228V and P299S were predicted as probably damaging by PolyPhen online service, while mutations L49V, R285G, R285S, P299S and K421N would lead to a significant increase of free energy difference (ΔΔG > 1) indicated a destabilization of protein structure. Conclusions Evidences in the present investigation supported that PfTRAP gene from Bioko Island and other malaria endemic countries is highly polymorphic (especially at T cell epitopes), which provided the genetic information background for developing an PfTRAP-based universal effective vaccine. Moreover, some mutations have been shown to be detrimental to the protein structure or function and deserve further study and continuous monitoring.


2021 ◽  
Vol 19 (1) ◽  
pp. 20-28
Author(s):  
Abush Tesfaye Abebe ◽  
Adesike Oladoyin Kolawole ◽  
Nnanna Unachukwu ◽  
Godfree Chigeza ◽  
Hailu Tefera ◽  
...  

AbstractSoybean (Glycine max (L.) Merr.) is an important legume crop with high commercial value widely cultivated globally. Thus, the genetic characterization of the existing soybean germplasm will provide useful information for enhanced conservation, improvement and future utilization. This study aimed to assess the extent of genetic diversity of soybean elite breeding lines and varieties developed by the soybean breeding programme of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. The genetic diversity of 65 soybean genotypes was studied using single-nucleotide polymorphism (SNP) markers. The result revealed that 2446 alleles were detected, and the indicators for allelic richness and diversity had good differentiating power in assessing the diversity of the genotypes. The three complementary approaches used in the study grouped the germplasm into three major clusters based on genetic relatedness. The analysis of molecular variance revealed that 71% (P < 0.001) variation was due to among individual genotypes, while 11% (P < 0.001) was ascribed to differences among the three clusters, and the fixation index (FST) was 0.11 for the SNP loci, signifying moderate genetic differentiation among the genotypes. The identified private alleles indicate that the soybean germplasm contains diverse variability that is yet to be exploited. The SNP markers revealed high diversity in the studied germplasm and found to be efficient for assessing genetic diversity in the crop. These results provide valuable information that might be utilized for assessing the genetic variability of soybean and other legume crops germplasm by breeding programmes.


Weed Science ◽  
2007 ◽  
Vol 55 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Runzhi Li ◽  
Shiwen Wang ◽  
Liusheng Duan ◽  
Zhaohu Li ◽  
Michael J. Christoffers ◽  
...  

Weed genetic diversity is important for understanding the ability of weeds to adapt to different environments and the impact of herbicide selection on weed populations. Genetic diversity within and among six wild oat populations in China varying in herbicide selection pressure and one population in North Dakota were surveyed using 64 polymorphic alleles resulting from 25 microsatellite loci. Mean Nei's gene diversity (h) for six wild oat populations from China was between 0.17 and 0.21, and total diversity (HT) was 0.23. A greater proportion of this diversity, however, was within (Hs= 0.19) rather than among (Gst= 0.15) populations. For the wild oat population from the United States,h= 0.24 andHT= 0.24 were comparable to the values for the six populations from China. Cluster analysis divided the seven populations into two groups, where one group was the United States population and the other group included the six Chinese populations. The genetic relationships among six populations from China were weakly correlated with their geographic distribution (r= 0.22) using the Mantel test. Minimal difference in gene diversity and small genetic distance (Nei's distance 0.07 or less) among six populations from China are consistent with wide dispersal of wild oat in the 1980s. Our results indicate that the wild oat populations in China are genetically diverse at a level similar to North America, and the genetic diversity of wild oat in the broad spatial scale is not substantially changed by environment, agronomic practices, or herbicide usage.


Author(s):  
R. H. Sammour ◽  
M. A. Karam ◽  
Y. S. Morsi ◽  
R. M. Ali

Abstract The present study aimed to assess population structure and phylogenetic relationships of nine subspecies of Brassica rapa L. represented with thirty-five accessions cover a wide range of species distribution area using isozyme analysis in order to select more diverse accessions as supplementary resources that can be utilized for improvement of B. napus. Enzyme analysis resulted in detecting 14 putative polymorphic loci with 27 alleles. Mean allele frequency 0.04 (rare alleles) was observed in Cat4A and Cat4B in sub species Oleifera accession CR 2204/79 and in subspecies trilocularis accessions CR 2215/88 and CR 2244/88. The highest genetic diversity measures were observed in subspecies dichotoma, accession CR 1585/96 (the highest average of observed (H0) and expected heterozygosity (He), and number of alleles per locus (Ae)). These observations make this accession valuable genetic resource to be included in breeding programs for the improvement of oilseed B. napus. The average fixation index (F) is significantly higher than zero for the analysis accessions indicating a significant deficiency of heteozygosity. The divergence among subspecies indicated very great genetic differentiation (FST = 0.8972) which means that about 90% of genetic diversity is distributed among subspecies, while 10% of the diversity is distributed within subspecies. This coincides with low value of gene flow (Nm = 0.0287). B. rapa ssp. oleifera (turnip rape) and B. rapa ssp. trilocularis (sarson) were grouped under one cluster which coincides with the morphological classification.


2011 ◽  
Vol 77 (4) ◽  
pp. 299-304
Author(s):  
Maria Krzakowa ◽  
Zbigniew Celka

The genetic Variation of Reed Grass <em>Calamagrostis arundinacea</em> (L.) Roth was investigated in 25 populations in various geographic regions of Poland. A total of 907 individuals were sampled for electrophoretic analysis of peroxidase loci (11 allozymes). Populations were characterised by genetic parameters e.g. heterozygosity level, Wright's fixation index (F) and polymorphism coefficient (Pg). Mean values of interpopulation variability level (GST=0.0310), total genetic diversity (HT=0.4102) and gene flow between populations (Nm=7.805) were also examined. All the populations were polymorphic and they remain in Hardy Weinberg equilibrium.


2020 ◽  
Vol 24 (7) ◽  
pp. 747-754
Author(s):  
V. R. Kharzinova ◽  
N. A. Zinovieva

One of the main tasks of genetics and animal breeding is the assessment of genetic diversity and the study of genetic relationships between different breeds and populations using molecular genetic analysis methods. We analysed the polymorphism of microsatellites and the information on the state of genetic diversity and the population structure of local breeds in Russia: the Kemerovo, the Berkshire, the Liven, the Mangalitsa, and the Civilian; in the Republic of Belarus: the Large White and the Black-and-White; and in Ukraine: the White Steppe, as well as commercial breeds of imported origin of domestic reproduction: the Large White, the Landrace, and the Duroc. The materials used for this study were the tissue and DNA samples extracted from 1,194 pigs and DNA of the UNU “Genetic material bank of domestic and wild animal species and birds” of the L.K. Ernst Federal Research Center for Animal Husbandry. Polymorphisms of 10 microsatellites (S0155, S0355, S0386, SW24, SO005, SW72, SW951, S0101, SW240, and SW857) were determined according to the previously developed technique using DNA analyser ABI3130xl. To estimate the allele pool of each population, the average number of alleles (NA), the effective number of alleles (NE ) based on the locus, the rarified allelic richness (AR), the observed (HO ) and expected (HE ) heterozygosity, and the fixation index (FIS) were calculated. The degree of genetic differentiation of the breeds was assessed based on the pairwise values of FST and D. The analysis of the allelic and genetic diversity parameters of the local breeds showed that the maximum and minimum levels of polymorphism were observed in pigs of the Ukrainian White Steppe breed (NA = 6.500, NE = 3.709, and AR = 6.020) and in pigs of the Duroc breed (NA = 4.875, NE = 2.119, and AR = 3.821), respectively. The highest level of genetic diversity was found in the Large White breed of the Republic of Belarus (HO = 0.707 and NE = 0.702). The minimum level of genetic diversity was found in pigs of the imported breeds – the Landrace (HO = 0.459, HE = 0.400) and the Duroc (HO = 0.480, HE = 0.469) – indicating a high selection pressure in these breeds. Based on the results of phylogenetic analysis, the genetic origin of Large White pigs, the breeds, from which the Berkshire pigs originated, and the genetic detachment of the Landrace from the Mangalitsa breeds were revealed. The cluster analysis showed a genetic consolidation of the Black-and-White, the Berkshire, and the Mangalitsa pigs. Additionally, the imported breeds with clustering depending on the origin were characterised by a genetic structure different from that of the other breeds. The information obtained from these studies can serve as a guide for the management and breeding strategies of the pig breeds studied, to allow their better use and conservation.


2018 ◽  
Vol 7 (4.38) ◽  
pp. 122
Author(s):  
Kairat Dossybayev ◽  
Aizhan Mussayeva ◽  
Bakytzhan Bekmanov ◽  
Beibit Kulataev

The genetic structure of three Kazakh sheep breeds was examined by using 12 microsatellite loci. A total of 144 alleles were detected from the 12 STR loci, with a mean value of 12.0. The highest allele diversity was found at the locus CSRD247 (16 alleles). PIC value showed that all studied STR markers are more informative and appropriate for genetic analysis of three Kazakh sheep populations. Beside of INRA006, all markers had high level of genetic variability. As Fixation index shows, the excess of the heterozygosity was observed only in loci MAF065. Obtained number of private alleles in Edilbai, Kazakh Arkhar Merino and Kazakh Fine-wool sheep were 25, 17 and 15 respectively. Genetic diversity was higher in Edilbai population than in other two populations. The genetic variability was lower in Kazakh Arkhar Merino sheep than in the Edilbai and Kazakh Fine-wool sheep breeds. The genetic distance was the largest between Edilbai and Kazakh Arkhar Merinos. Also, the moderate differentiation was observed between Edilbai and Kazakh Arkhar Merinos.   


2020 ◽  
Author(s):  
Pierre Teodósio Felix ◽  
Dallynne Bárbara Ramos Venâncio ◽  
Eduarda Doralice Alves Braz Da Silva ◽  
Robson da Silva Ramos

AbstractIn this work, we evaluated the levels of genetic diversity in 18 genomes of SARS-CoV-2 carrying the D614G mutation, coming from Malaysia and Venezuela and publicly available at the National Center of Biotechnology and Information (NCBI). These haplotypes were previously used for phylogenetic analysis, following the LaBECom protocols. All gaps and unconserved sites were extracted for the construction of a phylogenetic tree. As specific methodologies for paired FST estimators, Molecular Variance (AMOVA), Genetic Distance, mismatch, demographic and spatial expansion analyses, molecular diversity and evolutionary divergence time analyses, 20,000 random permutations were always used. The results revealed the presence of only 57 sites of polymorphic and parsimonium-informative among the 29,827bp analyzed and the analyses based on FST values confirmed the presence of two distinct genetic entities with fixation index of 22% and with a higher component of population variation (78.14%). Tau variations revealed a significant time of divergence, supported by mismatch analysis of the observed distribution (τ = 42%). It is safe to say that the small number of existing polymorphisms should not reflect major changes in the protein products of viral populations in both countries and this consideration provides the safety that, although there are differences in the haplotypes studied, these differences are minimal for both regions analyzed geographically and, therefore, it seems safe to extrapolate the levels of polymorphism and molecular diversity found in the samples for other mutant genomes of SARS-CoV-2 in other countries. This reduces speculation about the possibility of large differences between mutant strains of SARS-CoV-2 (D614G) and wild strains, at least at the level of their protein products, although the mutant form has higher transmission speed and infection. The analyses suggest that possible variations in protein products, of the wild virus in relation to its mutant form, should be minimal, bringing peace of mind as to the increased risk of death from the new form of the virus, as well as possible problems of gradual adjustments in some molecular targets for vaccines.


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